Bug Description

Use case:
- user tries to switch to one of the two instances of app 1
- user reveals the laucher by pushing the mouse cursor to the left: the launcher unhides
- user clicks on the icon of app 1: the first instance of app 1 is focused; user does *not* move the mouse
- in an eye wink, the user sees that there are multiple instances (indicated by multiple arrows)
- just when then user wants to click again to use expose, the launcher hides again
- trying to get expose, the user clicks (again), but because the launcher is hidden, this is taken as an app click
- .... so the user has to unreveal the launcher, etc.

This can this be solved in several ways:
1. longer time-out before the launcher hides again (1 - 2 seconds?)
2. do not hide the launcher until the mouse cursor is moved away; this is the way it works in unity-2d where there is no problem using expose
3. always use expose in case of multiple instances